[Speex-dev] frame_size parameter

[Jean-Marc Valin]

The speex_echo_capture() and speex_echo_playback have not been converted
to the new API. You'll have to use spexe_echo_cancellation() instead

	Jean-Marc

Daniel a écrit :
> Hi Jean,
> 
> Thank you for your reply.
> 
> Ok... I'm gonna use 'samples per channel' everywhere I see 'samples'...
> but what about  the 'speex_echo_playback' function ?
> 
> it does the following loop:
> 
> ...
> for (i=0;i<st->frame_size;i++)
>    st->play_buf[st->play_buf_pos+i] = play[i];
> ...
> 
> So... if frame size is 'samples per channel' it will copy only half the
> play buffer since there are two channels interleaved (supposing the play
> buffer is stereo of course)
> 
> I think it should take into account the number of channels, resulting in
> something like:
> 
> ...
> for (i=0;i<st->frame_size * play_channels;i++)
>    st->play_buf[st->play_buf_pos+i] = play[i];
> ...
> 
> 
> Sorry if what I said doesn't make any sense... I'm just trying to
> understand how could it work on more than one channel.
> Am I missing something ?
> Thank you!
> Daniel
> 
> 
> 
> 
> 
> Jean-Marc Valin escreveu:
>> In stereo mode, you need to use the init_mc() call and consider the
>> number of samples *per channel*. Also, more than 20 ms frames are a bad
>> idea.
>>
>>     Jean-Marc
>>
>> danflu at uninet.com.br a écrit :
>>  
>>> Hi,
>>>
>>> I'm using the echo cancellation api and I would like to
>>> clarify the 'frame_size' parameter used in
>>> speex_echo_state_init(frame_size,filter_length).
>>>
>>>
>>> In the 'docs' it says:
>>>
>>> "...where frame_size is the amount of data (in samples)you
>>> want to process at once..."
>>>
>>> So... here are my questions:
>>>
>>> if I use stereo input/output do I have to put the samples
>>> doubled ?
>>> For example... if I'm using 100 ms on mono 8khz I just pass
>>> 800 as 'frame_size', but if I switch on using stereo will I
>>> have to put 1600 samples to represent the same 100 ms? I'm
>>> looking at the code of 'speex_echo_playback' and I see the
>>> following snippet:
>>>
>>> ...
>>> for (i=0;i<st->frame_size;i++)
>>>     st->play_buf[st->play_buf_pos+i] = play[i];
>>> ...
>>>
>>> So... if my buffer is stereo and I put 800 samples as
>>> 'frame_size' the previous loop will just copy half of the
>>> 'play' buffer data (50 ms) or am I missing something ?
>>>
>>> Thanks in advance,
>>> Daniel
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Speex-dev mailing list
>>> Speex-dev at xiph.org
>>> http://lists.xiph.org/mailman/listinfo/speex-dev
>>>
>>>
>>>     
>>
>>
>>   
> 
> 
> 
> Jean-Marc Valin escreveu:
>> In stereo mode, you need to use the init_mc() call and consider the
>> number of samples *per channel*. Also, more than 20 ms frames are a bad
>> idea.
>>
>>     Jean-Marc
>>
>> danflu at uninet.com.br a écrit :
>>  
>>> Hi,
>>>
>>> I'm using the echo cancellation api and I would like to
>>> clarify the 'frame_size' parameter used in
>>> speex_echo_state_init(frame_size,filter_length).
>>>
>>>
>>> In the 'docs' it says:
>>>
>>> "...where frame_size is the amount of data (in samples)you
>>> want to process at once..."
>>>
>>> So... here are my questions:
>>>
>>> if I use stereo input/output do I have to put the samples
>>> doubled ?
>>> For example... if I'm using 100 ms on mono 8khz I just pass
>>> 800 as 'frame_size', but if I switch on using stereo will I
>>> have to put 1600 samples to represent the same 100 ms? I'm
>>> looking at the code of 'speex_echo_playback' and I see the
>>> following snippet:
>>>
>>> ...
>>> for (i=0;i<st->frame_size;i++)
>>>     st->play_buf[st->play_buf_pos+i] = play[i];
>>> ...
>>>
>>> So... if my buffer is stereo and I put 800 samples as
>>> 'frame_size' the previous loop will just copy half of the
>>> 'play' buffer data (50 ms) or am I missing something ?
>>>
>>> Thanks in advance,
>>> Daniel
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Speex-dev mailing list
>>> Speex-dev at xiph.org
>>> http://lists.xiph.org/mailman/listinfo/speex-dev
>>>
>>>
>>>     
>>
>>
>>   
> 
> 
>